Top 8 causes of v-belt failure - Acorn Industrial Services

Author: Elva

Jul. 28, 2025

0 0 0

Top 8 causes of v-belt failure - Acorn Industrial Services

V-belts are a low maintenance solution which are suitable for mid to high power belt drives, delivering a high level of efficiency. This makes v-belts amongst the most common components in modern machinery, found in almost every industry, from agriculture to pharmaceuticals.

If you are looking for more details, kindly visit our website.

We have been speaking to Power Transmission Product Manager, Paul Speight about what exactly it is that causes premature v-belt failure in a range of industries, and how we can help you to get the most out of your v-belts.

Visually examine your v-belts to check for any of the below symptoms to combat premature failure and unplanned downtime:

1. Rapid sidewall wear

Although side wall wear is inevitable over time, rapid sidewall wear can be a sign of a bigger problem, as most commonly it can be attributed to worn or damaged pulleys. However, there are many other possible influencing factors such as: using belts in extreme heat, excessive oil, grease, moisture and other generally abrasive environments can also cause this type of wear.

Solution: Ensuring pulleys are replaced when changing belts is important to be certain that you are getting the most from your belt systems. If the pulley wall is bright and shiny then it’s time to replace it.

2. Worn cover on back

Most commonly, back wear is a direct cause of the belt being forced or pried on to the pulley or that there is some misplaced slack within the belt which is causing damage by vibrating against the idler during operation. Although, on some occasions defective or worn backside idlers can contribute to worn backside covers, although this is less common.

Solution: Making sure that your belts have the correct tension on installation is essential. Even belts that are measured correctly and considered ‘fit and forget’ such as Optibelt Red Power 3, need to be re-tensioned within 24-48 hours of installation.

3. Belt soft, swollen

Excessive exposure to oil or grease can be a recipe for disaster for some v-belts as these products can cause belts to soften and become swollen, and thus no longer fitting properly into the pulley groove. This sort of problem could also be similarly attributed to the use of belt dressing.

Solution: If belts are working in extreme conditions, likelihood is that it’s not reaching its full potential. A simple belt guard can prevent foreign bodies including oil & grease from contaminating the drive, while it’s always worth noting that belt dressings are to be avoided. If oil and grease is still a problem, consider using a composite v-belt such as Fenner PowerTwist belting as they are generally unaffected by oil, grease, water and common industrial solvents.

4. Belt slips, squeals (spin burn)

Spin burn can be caused by worn or damaged pulleys and incorrect tensioning, which can wreak havoc on your belts, causing damage and ultimately, premature failure. This can also be less commonly caused by using the wrong belt cross-section or type, excessive oil, excessive grease or moisture and insufficient wrap on a small pulley.

Solution: This type of wear means it’s time to check your pulleys and belt tension as under tensioned belts and smooth pulleys mean unnecessary wear. You may well find that you need new pulleys or to re-tension your V-belt.

5. Split belt cover

There’s a lot to be said about the damage that can be caused by forcing a belt onto a pulley or running your V-belts with the incorrect tension, as this is the most common cause for many types of belt damage, including cover splits.

Solution: If you’re sure that there are no foreign objects in the grooves that could be causing the issue, then ensuring regular belt tensioning and that the correct size belts are ordered every time, you can help to avoid this issue.

6. Underside cracked

Cracking in belts can cause serious issues, particularly if they are left untreated as they can affect drive efficiency and eventually cause belt failure. Cracks commonly begin to appear on belts that are being exposed to excessive heat. Although it cannot always be exclusively attributed to this, as pulleys and backside idlers that are too small or misaligned can also cause this cracking.

Solution: If your v-belts are working in extreme temperatures, it may be time to consider an EPDM rubber belt that is designed to be able to withstand these temperatures without premature or unnecessary failure.

7. Missing cogs

Missing cogs can cause belts to slip and fail, when it is discovered there are teeth missing, the belt should be changed immediately. The most common reasons your belt could be missing a cog are excessive heat, the pulleys are too small or misaligned. It can also be caused by improper or prolonged storage of belts.

Solution: Once again, if your cogged v-belts are working in extreme temperatures, it may be ideal to consider belts designed for these environments. Additionally, establishing that your pulleys are correctly aligned using a laser alignment tool can eliminate the possible cause and improve machine running.

8. Cracked Bushings

Having cracked bushings means your drive is in dangerous territory, if the damage becomes too severe, your pulleys may not be attached securely to the shaft. Bushings can become cracked due to excessive tension from the drive or using worn or damaged pulleys.

Solution: Over-tensioning belts can be just as damming to your v-belts as under-tensioning, using a belt tension gauge to check belt tension can help you avoid unnecessary bushing damage.

Paul’s top tips to prevent premature failure

V-belt drives really don’t need a lot of attention to be efficient, but getting the basics right can avoid these types of failure and really improve the life span of your belts and pulleys to ensure you get the optimum efficiency from your components.

V-Belt Code Guide: How to Read V-Belt Numbers - Blog

A machine with two shafts definitely needs to transmit power from one shaft to the other. In other to carry out this task seamlessly, the use of power transmission devices such as chains, gears, and belts, in particular, are adopted. Of all mentioned means, one is highly flexible, seamless, effective, and also an efficient power transmission device, which is popularly known as V-Belt.

What is V-Belt?

“V-belts” as it sounds, was coined from the letter V looks of this particular belt. We can also say its name is gotten from its trapezoidal shape. The V-Belt helps to transmit force out from the engine straight to the ancillary elements, which also includes the alternator. The primary source of the seamless task done by the V-Belt comes from the rotation of the crankshaft, which helps to drive one or two units of an engine.

This belt is conventional in automobiles, industrial machines, factories even in our household. The V-Belt was made from twisted synthetic fibrous tensile, which is compressed by synthetic rubber, this strengthens the belt and makes it more flexible. Compared to the other power transmission devices, V-Belts does not require any form of maintenance or lubrication, as it is the case for chains.

In industries and some manufacturing factories, the majority of the machines you get to see there are operated with the V-Belt as it is the primary power transmission device that also provides a suitable combination for loading of the bearings, speed, traction, and even longevity.

It is widely known that V-Belts solve slipping and alignment problems, it can never go wrong while in operation compared to other power transmission devices.

V-Belts can also be found in modern automobiles (In the past, roller chains were used to transmit power in vehicles) and in our households such as washing machines and lawn mowers. As long as we make use of one or two machines regardless of its size, V-Belt keeps it in motion.

Types of V-Belts:

There are three common type of V-belts, and they are classified by their dimensions:

1) Classical V-Belt - Classified by its dimensions ranging from A to E

You will get efficient and thoughtful service from Colorful.

The classical V-Belt is the most common of all V-Belt types, and it has been in existence even before other V-Belt types. This type of V-Belt has a broad scope of usage in different areas such as Agriculture, Industrial Machinery, ventilation etc. and this is due to the fact that it covers a load range from 1 horsepower to 500 horsepower. There is no doubt that the Narrow Wedge is more efficient than the classical V-Belt; however, they work seamlessly with higher bearing loads and have a high tolerance for adverse operating conditions.

2) Narrow Wedge - Classified by its dimensions ranging from 3V, 5V, and 8V

This type of V-Belt is more efficient than the Classical type as they have the most significant degree possible for the distribution of force and load transfer, which is the main advantage over the Classical type. Narrow Wedge is able to transmit three times the Horsepower a classical V-Belt would in the same drive space; they are very suitable for drives at high speed and its well-known for its sturdy, compact size. Unlike the classical V-Belt, Narrow Wedge can handle drives from 1 horsepower to 1,000 horsepower.

3) Fractional Horsepower - Classified by its dimensions ranging from 2L, 3L, 4L, 5L.

Unlike the two mentioned types of V-Belts, the Fractional Horsepower is different in operation as it is only designed for light loads and is often used as a single belt on drives that run at one Horsepower or even less. This type of belt is what you see in domestic machines popular in household equipment such as washing machines, fans, and refrigerators. Fractional Horsepower can never be used on any heavy-duty industrial machinery even if it fits perfectly well.

Note: Unit of Measurements Depending on the type of belts and the origin of the manufacturer, some belts have a unit of measurement in milimeters (mm) whilst others are measured in inches. For instance, classical belts and American standard type belts are measured in inches, belts in the modern range are mostly denoted in mm.

How to Measure V-Belt

There are times when you will need to replace your V-Belt due to its natural wear and tear. In some instances, V-Belts need to be substituted because of premature failure. You could prevent this by looking out for these warning signs.

To order the correct replacement V-Belt, it is as simple as taking a few quick measurements as shown in the steps below:

Step 1: Determine the type of belt you have. You need to measure the width of your belt. We have different types of belts, Type A, Type B, with different measurements. So you want to know the width of your belt first

Step 2: Measure the length of your belt. You can do this by using a cloth or a measuring tape. To get a correct length, place your belt on a steel tape.

Step 3: Subtract from the outside measurement. If you know the type of V-Belt you have already, there will be need to subtract a specific inch from the size to select the correct V-Belt

For type A, you subtract 2 Inches

For type B, you subtract 3 inches.

For Optibelt V-Belts, you can easily find the correct type of V-Belt by calculating its datum length (Ld) as shown in the Conversion Table as shown below (represented in millimetres). The datum length determines the Part Number of the V-Belt.

To be precise, you would need to determine if the measurement is taken from the inside length (Li) or outside length (La) of the V-Belt.

Example:

If we measured the outside length of a SPA belt and it is measured at La = mm.

In the highlighted table above, we can see that the formula for SPA is La= Ld+18.

To calculate the datum length, you subtract 18 from the outside length of mm:

Ld = -18 = .

Based on the calculation above, we now know that the Part Number of the V-Belt is SPA .

How to Read V-Belt Codes

V-Belt codes allow us to identify the belt profile and its length. Follow the simple steps below to learn how to read V-belt codes:

Step 1: Outside the surface of your belt, you will find the prefix e.g. B, 3L.. etc. This is also known as the belt profile.

Note: Prefix Depending on the manufacturer, the belt profile on the surface of the belt can be represented by a letter such as A, B etc. or an alphanumeric value, such as 3L, 4L etc.

Step 2: After the belt profile, read the two or three digit number that follows to identify the length of your belt. Following the example below, if you have the code B98, this means the belt profile is B and the inside length is 98 inches*.

The code B98 shows the belt profile, B and its inside length at 98 inches*

V-Belt in Motion

Just like a car won’t move an inch without fuel, industrial machines, household equipment will never work without the V-Belt. This tells how important it is to have V-Belt in machines. Remember in manufacturing industries, motion is needed for machines to carry out designated tasks and the most efficient way to give two end of shafts is where the V-Belt comes into play. Its benefits cannot be underestimated.

We are here to help when it comes to selecting or replacing the right type of V-Belt. As an authorized distributor of Optibelt, we provide a range of V-Belts that suits your need. Alternatively, if you would like to find out more information about V-Belts, get in touch with us below:

* Previously, we mentioned that the belt length was 98mm. Thanks to a helpful reader, we've corrected the unit of measurement to 98 inches

Are you interested in learning more about Excavator V Belt? Contact us today to secure an expert consultation!

None

Top 5 Tips for Buying a Reliable Used Hyundai Excavator

Comments

More Categories You Might Be Interest